The present invention relates to compounds having e.g. antimicrobial, e.g. antibacterial, activity; more specifically the present invention relates to mutilins.
In one aspect the present invention provides a compound of formula 
wherein
R is hydrogen or alkyl;
R1 is hydrogen or a group of formula 
xe2x80x83wherein
X is sulphur, oxygen, NR10, wherein R10 is hydrogen or alkyl, or N+(Rxe2x80x210)2 wherein Rxe2x80x210 is alkyl in the presence of an appropriate anion;
R9 is amino, alkyl, aryl, heterocyclyl or mercapto; and, if X is oxygen, R9 is additionally hydrogen;
R2 is arylene or heterocyclene;
R4 is hydrogen or alkyl;
R5 is hydrogen or alkyl;
R3 and R3xe2x80x2 are hydrogen or deuterium,
R6, R7 and R8 are hydrogen or deuterium; or
R and R2 together with the nitrogen atom to which they are attached form non-aromatic heterocyclene and R1 is a group of formula 
xe2x80x83wherein X and R9 are as defined above.
R is hydrogen or alkyl, e.g. (C1-4)alkyl; preferably hydrogen.
R1 is hydrogen or a group of formula xe2x80x94C(xe2x95x90X)R9, e.g. a group of formula xe2x80x94C(xe2x95x90X)R9.
X is sulphur, oxygen, NR10, wherein R10 is hydrogen or alkyl, e.g. (C1-4)alkyl, or N+(Rxe2x80x210)2 wherein Rxe2x80x210 is alkyl, e.g. (C1-4)alkyl, in the presence of an appropriate anion; preferably oxygen.
R9 is amino, alkyl, alkoxy, e.g. (C1-4)alkoxy; aryl, heterocyclyl or mercapto; e.g. a group of formula xe2x80x94Sxe2x80x94R12, wherein R12 is alkyl, e.g. (C1-4)alkyl; and, if X is oxygen, R9 is hydrogen, amino, alkyl, alkoxy, aryl, heterocyclyl or mercapto.
R9 is preferably alkyl, e.g. (C1-8)alkyl, such as (C1-4)alkyl, e.g. unsubstituted or substituted alkyl, e.g. substituted by groups which are conventional in pleuromutilin chemistry, e.g. one or more amino, halogen, such as fluoro, e.g. trifluoroalkyl, such as trifluoromethyl; guanidinyl, hydroxy, heterocyclyl, e.g. including a 5 or 6 membered ring containing 1 or 2 nitrogen atoms; e.g. imidazolyl. If R9 is alkyl substituted by amino, R9 is preferably the residue of an amino acid, e.g. including valine, histidine, arginine, pipecolinic acid, e.g. said residue includes that part of an amino acid which remains if the carboxylic group is split off.
Or R9 is preferably heterocyclyl, e.g. 5 or 6 membered heterocyclyl, e.g. containing one or two heteroatoms; e.g. selected from nitrogen; e.g. condensed with a further ring (system), e.g. the further ring system including phenyl; preferably piperidinyl, pyrrolidinyl, pyrrolyl, pyridinyl, benzimidazolyl, quinolinyl, triazolyl; e.g. unsubstituted heterocyclyl or substituted heterocyclyl, e.g. substituted by one or more alkyl, e.g. methyl; hydroxy, amino, nitro, a group COOR13, wherein R13 is alkyl, e.g (C1-4)alkyl, such as tert.butyl; e.g. preferably substituted by one or more alkyl hydroxy, amino, nitro.
If R9 is heterocyclyl, e.g. piperidinyl, hydrogen atoms of the heterocyclyl ring, e.g. in piperidinyl; the hydrogen atom attached to the nitrogen atom of the ring system may be replaced by deuterium.
Amino in the meaning of R9 includes a free amine group, alkyl- and dialkylamine and amine substituted by xe2x80x94COOR11, wherein R11 is alkyl, preferably (C1-4)alkyl. R2is arylene, such as phenylene, e.g. unsubstituted arylene or substituted arylene, e.g. substituted by groups which are conventional in pleuromutilin chemistry; e.g. one or more hydroxy, alkyl, e.g. (C1-4)alkyl; halogen, e.g. fluoro; trifluoroalkyl; nitro; or heterocyclene. Heterocyclene as used herein is a heterocyclic ring, wherein two bonds are the bonds to the vicinal nitrogen and sulphur group in a compound of formula I. Preferably R2 is arylene, e.g. unsubstituted arylene or arylene substituted by one or more groups which are conventional in pleuromutilin chemistry, e.g. alkyl, e.g. (C1-4)alkyl, such as methyl; halogen such as fluoro; trifluoroalkyl, such as trifluoromethyl. Arylene and heterocyclene in the meaning of R2 are bound to a sulphur atom and to xe2x80x94N(R)(R1) in a compound of formula I. These two bonds may be vicinal or in another position, e.g. in ortho, para or meta position; in the corresponding ring system. Heterocyclene is preferably bound to the sulphur atom and to xe2x80x94N(R)(R1) in a compound of formula I via carbon atoms of heterocyclene.
R4 is hydrogen or alkyl; preferably hydrogen or (C1-4)alkyl, e.g. methyl.
R5 is hydrogen or alkyl, preferably hydrogen or (C1-4)alkyl such as methyl; e.g. unsubstituted alkyl or substituted alkyl, e.g. substituted by hydroxy; more preferably R5 is hydrogen.
R3 and Rxe2x80x23 are hydrogen or deuterium, preferably hydrogen. R6, R7 and R8 are hydrogen or deuterium.
If R1 is a group of formula xe2x80x94C(xe2x95x90X)xe2x80x94R9, R and R2 together with the nitrogen atom to which they are attached may form non-aromatic heterocyclene, e.g. having 5 to 6 ring members and one heteroatom, e.g. nitrogen; preferably including piperidinyl, pyrrolidinyl, preferably piperidine. Preferably said heterocyclene is bound to the sulphur group and to the xe2x80x94N(R1) group in a compound of formula I via heterocyclene carbon atoms.
If not otherwise defined herein heterocyclyl or heterocyclene includes a 5 or 6 membered ring having 1 to 4 heteroatoms selected from S, O and N; e.g. N; optionally condensed with a further ring (system), e.g. condensed with a phenyl ring; e.g. or condensed with a heterocyclyl ring, e.g. including quinoline, purine. Heterocycl(ene) includes unsubstituted or substituted heterocycl(ene), e.g. substituted by groups which are conventional in pleuromutilin chemistry, e.g. including alkyl; hydroxy, amino, nitro, a group COOR13, wherein R13 is alkyl. Alkyl includes (C1-8)alkyl, e.g. (C1-4)alkyl. Aryl includes phenyl.
In another aspect the present invention provides a compound of formula I, wherein
R is hydrogen;
R1 is hydrogen or a group of formula 
xe2x80x83wherein X is sulphur, oxygen, NR10, wherein R10 is hydrogen or alkyl, or N+(Rxe2x80x210)2 wherein
Rxe2x80x210 is alkyl in the presence of an appropriate anion; e.g. Clxe2x88x92;
R9 is amino, alkyl, heterocyclyl or mercapto; and, if X is oxygen, R9 is additionally hydrogen;
R2 is phenylene;
R4 is hydrogen or alkyl;
R5 is hydrogen;
R3 and R3xe2x80x2 are hydrogen;
R6, R7 and R8 are hydrogen or deuterium; or
R and R2 together with the nitrogen atom to which they are attached form non-aromatic heterocyclene and R1 is a group of formula 
xe2x80x83wherein X is oxygen and R9 is alkyl.
In another aspect the present invention provides a compound of formula 
wherein R1s is hydrogen or a group of formula 
e.g. a group of formula 
wherein R6s is hydrogen or deuterium;
R2s is hydrogen, methyl or tert-butyl;
R7s is hydrogen or methyl; and
R3s, R4s and R5s are hydrogen or deuterium; and a compound of formula 
xe2x80x83wherein R3ss, R4ss and R5ss are hydrogen or deuterium.
A compound of formula I includes a compound of formulae Is and Iss.
In another aspect the.present invention provides a compound of formula I, e.g. including a compound of formula Is and Iss in the form of a salt, or in the form of a salt and in the form of a solvate, or in the form of a solvate.
In another aspect the present invention provides
14-O-(3-amino)phenyl-sulfanylacetyl)-mutilin, e.g. in free form or in the form of a salt, e.g. with hydrochloric acid;
14-O-(3-amino)phenyl-sulfanylacetyl)-2,2,4-trideutero-mutilin, e.g. in free form or in the form of a salt, e.g. with hydrochloric acid or with deuterochloric acid;
14-O-(3-(piperidin-2-yl-carbonylamino)-phenyl-sulfanylacetyl)mutilin, e.g. in free form or in the form of a salt, e.g. with hydrochloric acid;
14-O-(3-(piperidin-2-yl-carbonylamino)phenyl-sulfanylacetyl) -2,2,4-trideutero-mutilin, e.g. in free form or in the form of a salt, e.g. with hydrochloric acid or deuterochloric acid;
14-O-(3-(piperidin-2-yl-carbonylamino)-2,5-dimethyl-phenylthio-methylcarbonyl)mutilin, e.g. in free form or in the form of a salt, e.g. with hydrochloric acid;
14-O-(3-(piperidin-2-yl-carbonylamino)-2,5-dimethyl-phenylthio-methylcarbonyl)-2,2,4-trideutero-mutilin, e.g. in free form or in the form of a salt, e.g. with hydrochloric acid or with deuterochloric acid;
14-O-(3-(piperidin-2-yl-carbonylamino)-5-tert.butyl-phenyl-sulfanylacetyl)mutilin, e.g. in free form or in the form of a salt, e.g. with hydrochloric acid;
14-O-(3-(piperidin-2-yl-carbonylamino)-5-tert.butyl-phenyl-sulfanylacetyl)-2,2,4-trideutero-mutilin, e.g. in free form or in the form of a salt, e.g. with hydrochloric acid or with deuterochloric acid;
14-O-(1(2-amino-isobutylcarbonyl)-piperidin-3-yl-sulfanylacetyl)mutilin, e.g. in free form or in the form of a salt, e.g. with hydrochloric acid; and
14-O-(1(2-amino-isobutylcarbonyl)-piperidin-3-yl-sulfanylacetyl)-2,2,4-trideutero-mutilin, e.g. in free form or in the form of a salt, e.g. with hydrochloric acid or with deuterochloric acid.
A salt of a compound of formula I includes a pharmaceutically acceptable salt, e.g. including a metal salt or an acid addition salt. Metal salts include for example alkali or earth alkali salts; acid addition salts include salts of a compound of formula I with an acid, e.g. hydrogen fumaric acid, fumaric acid, naphthalin-1,5-sulphonic acid, hydrochloric acid, deuterochloric acid; preferably hydrochloric acid or deuterochloric acid.
A compound of formula I in free form may be converted into a corresponding compound in the form of a salt; and vice versa. A compound of formula I in free form or in the form of a salt and in the form of a solvate may be converted into a corresponding compound in free form or in the form of a salt in unsolvated form; and vice versa.
In another aspect the present invention provides a compound of formula 
wherein
R1p is hydrogen, amino, alkyl, aminoalkyl or an optionally amino and/or hydroxy- and/or nitrosubstituted 5- or 6-membered heteroaromatic or heteroalicyclic ring with 1 to 3 nitrogen atoms;
R2p represents an optionally alkyl-, fluoro- or trifluoromethylsubstituted aromatic, 5- or 6-membered heteroaromatic with 1 to 3 nitrogen atoms, purine or quinoline;
R3p represents S or O; preferably S;
R4p represents hydrogen or methyl;
R5p represents hydrogen, methyl or CH2OH,
Xp represents NH or O; and
R6p, R7p and R8p are the same or different and represent hydrogen or deuterium, in free form or in form of an acid addition or quatemary salt.
A compound of formula I, including a compound of formulae Is, Iss and Ip, may exist in the form of isomers and mixtures thereof; e.g a compound of formula I may contain asymmetric carbon atoms and may thus exist in the form of diastereoisomeres and mixtures thereof. Isomeric or diastereoisomeric mixtures may be separated as appropriate, e.g. according to a method as conventional, to obtain pure isomers or diastereoismeres, respectively. The present invention includes a compound of formula I in any isomeric and diasteroisomeric form and in any isomeric and diastereoisomeric mixture.
Preferably the cofiguration in the mutilin ring of a compound of formula I is the same as in a naturally produced mutilin.
In another aspect the present invention provides a process for the production of a compound of formula I as defined above comprising the steps
Either,
a1. reacting a compound of formula 
xe2x80x83wherein R3, Rxe2x80x23, R4 and R5 are as defined in formula I and R6, R7 and R8 are hydrogen, with a compound of formula N(R)(R1)xe2x80x94R2xe2x80x94SH, wherein R, R1 and R2 are as defined in formula I, to obtain a compound of formula I, wherein R, R1, R2, R3, Rxe2x80x23, R4 and R5 are as defined in formula I and R6, R7 and R8 are hydrogen;
and, if desired,
b1. introducing deuterium into a compound of formula I obtained in step a1. to obtain a compound of formula I, wherein R6, R7 and R8 are deuterium, and R, R1, R2, R3, Rxe2x80x23, R4 and R5 are as defined in formula I;
or
a2. reacting of a compound of formula II as defined in step a1. with thiourea and subsequent reduction to obtain a compound of formula 
xe2x80x83wherein R3, Rxe2x80x23, R4 and R5 are as defined in formula I and R6, R7 and R8 are hydrogen,
b2. reacting a compound of formula III as defined in step a2. with a compound of formula R2(NO2)2, wherein R2 is as defined in formula I; or with a non-aromatic heterocyclic ring which carries a group of formula xe2x80x94C(xe2x95x90X)R9 wherein X and R9 are as defined in claim 1, in the form of a reactive derivative, e.g. a mesylate or a tosylate; to obtain a compound of formula 
xe2x80x83wherein R2, R3, Rxe2x80x23, R4 and R5 are as defined in formula I and R6, R7 and R8 are hydrogen,
c2. reducing the nitro group in a compound of formula IV as defined in step b2., to obtain a compound of formula I, wherein R2, R3, Rxe2x80x23, R4 and R5 are as defined in formula I and R, R1, R6, R7 and R8 are hydrogen; and, if desired,
d2. reacting the amino group in a compound of formula I, as defined in step c2., to obtain a compound of formula I, wherein R1 is a group of formula 
xe2x80x83wherein R, R2, R3, Rxe2x80x23, R4, R5, R9 and X are as defined in formula I and R6, R7 and R8 are hydrogen; and, if desired,
e2. introducing deuterium into a compound of formula I as defined in step d2., to obtain a compound of formula I, wherein R, R1, R2, R3, Rxe2x80x23, R4, R5, R9 and X are as defined in formula I and R6, R7 and R8 are deuterium;
or
a3. reacting a compound of formula 
xe2x80x83wherein R6, R7 and R8 are hydrogen and R3 and Rxe2x80x23 are hydrogen or deuterium, with a compound of formula 
xe2x80x83wherein R4 and R5 are as defined in formula I and Hal is halogen, e.g. chloro, bromo, iodo; to obtain a compound of formula 
xe2x80x83wherein R4, R5, Hal, R6, R7, R8, R3 and Rxe2x80x23 are as defined in step a3.;
b3. reacting a compound of formula VI as defined in step a3. with a compound of formula HSxe2x80x94R2(NO2)2, wherein R2 is as defined in formula I, to obtain a compound of formula IV as defined in step b2., and further reacting a compound of formula IV according to step c2., and if desired, according to any one of steps d2. and e2. as defined above, to obtain a compound of formula I as defined in formula I.
Any compound of formula I, e.g. including a compound of formulae Is, Iss or Ip; may be prepared as appropriate, e.g. according to a method as conventional, e.g. or as specified herein. Any compound of formulae Is, Iss and Ip may be prepared, e.g. analogously, according to a process for the preparation of a compound of formula I.
A compound of formula II and of formula V is known or may be obtained according to a method as conventional.
Replacement of hydrogen atoms in a compound of formula I, e.g. in the form of a salt; by deuterium atoms may be carried out as appropriate, e.g. according to a method as conventional, e.g. or according to a method described herein; e.g. by treatment of a compound of formula I, e.g. including a compound of formula Is, Iss and Ip; with deuterochloric acid (DCl) in an appropriate solvent (system) and isolation of a compound of formula I, e.g. in the form of a salt, wherein hydrogen atoms, e.g. in the meaning of R6, R7 and R8 are replaced by deuterium atoms.
The production of a compound of formula I, wherein R3 and Rxe2x80x23 is deuterium may be carried out as appropriate, e.g. according to a method as conventional, e.g. via treatment of a compound of formula V wherein the carbon atoms carrying R3 and Rxe2x80x23, which both are hydrogen, together form a double bond and which is a known compound, with deuterium to obtain a compound of formula V, wherein R3 and Rxe2x80x23 are deuterium; and further reacting a compound of formula V, wherein R3 and Rxe2x80x23 are deuterium as appropriate, e.g. according to a method as conventional, e.g. according to steps a3. to b3. as described above, to obtain a compound of formula I.
The compounds of formula I, e.g. including a compound of formulae Is, Iss and Ip, hereinafter designated as xe2x80x9cactive compound(s) of the present inventionxe2x80x9d exhibit pharmacological activity and are therefore useful as pharmaceuticals.
For example, the active compounds of the present invention show antimicrobial, e.g antibacterial, activity against gram negative bacterias, such as Escherichia coli; and against gram positive bacteria, such as Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Mycoplasms, Chalmydia and obligatory anaerobes, e.g. Bacteroides fragilis; in vitro in the Agar Dilution Test or Microdilution Test according to National Commftee for Clinical Laboratory Standards (NCCLS) 1997, Document M7-A4 Vol.17, No. 2: xe2x80x9cMethods for dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aerobicallyxe2x80x94Fourth Edition, Approved Standardxe2x80x9d; and e.g. in vivo in systemic infections in mice.
The active compounds of the present invention show antibacterial activitiy in vitro (MIC (xcexcg/ml)) in the Agar Dilution Test or in the Microdilution Test from about xe2x89xa60.01 xcexcg/ml to 25 xcexcg/ml, e.g. against above mentioned bacterial species; and are active against Mycoplasms and Chlamydia. MIC=minimal inhibitory concentration.
The active compounds of the present invention show activity in systemic infections of mice, e.g. against Staphylococcus aureus (e.g. strain ATCC 49951), e.g. when administered parenteral or oral, e.g. at dosages from about 8 to 150 mg/kg body weight; E.g. the ED50 values for the compound of example 23 is 7.55 mg/kg body weight after subcutaneous administration; and 7.72 mg/kg body weight after oral administration. ED50=Effective dosage in mg/kg body weight per application by which 50% of the treated animals are protected from death; calculated by Probit analysis (n=8 animals/group). It has, for example, been determined that the MIC 90% (xcexcg/ml) of the compounds of examples 1 and 52 against, for example Staphylococcus aureus, e.g. strains ATCC 10390, ATCC 29213, ATCC 29506, ATCC 49951 or ATCC 9144, is of ca. xe2x89xa60.0125 xcexcg/ml; whereas for example the MIC 90% (xcexcg/ml) of erythromycin A, as commercially available, is of ca. 0.2 to 0.4.
The active compounds of the invention show an surprising overall activity spectrum. For example, it has been determined that the active compounds of the present invention show surprising activity in vitro against Enterococcus faecium, including vancomycin-resistant strains; against Staphylococcus aureus including methicillin sensitive (MSSA) and methicillin-resistant (MRSA) strains; and against Streptococcus pneumoniae including penicillin-resistant strains; e.g. in the Agar Dilution Test or in the Micro Dilution Test in Mueller-Hinton agar or Mueller-Hinton broth with or without supplements according to the approved standard reference methods of the National Committee for Clinical Laboratory Standards (NCCLS), Document M7-A4 for aerobic bacteria.
For example it has been determined that the MIC (xcexcg/ml) the compounds of examples 1 and 52 (both tested in the form of a hydrochloride) against for example Staphylococcus aureus MSSA is of ca. 0.025; whereas the MIC (xcexc/ml) of azithromycin as commercially available is of ca. 1.6; that the MIC (xcexcg/ml) of the compound of example 1 against for example Staphylococcus aureus MRSA is of ca. xe2x89xa60.0125; whereas the MIC (xcexcg/ml) of azithromycin as commercially available is of ca.  greater than 25.6; that the MIC (xcexcg/ml) of the compounds of examples 1 and 52 against for example penicillin-resistant Streptococcus pneumoniae is of ca. xe2x89xa60.0125; whereas the MIC (xcexcg/ml) of azithromycin as commercially available is of ca.  greater than 2.56; and that the MIC of the compounds of examples 1 and 52 against for example vancomycin-resistant Enterococcus faecium is of ca. xe2x89xa60.0125 to 0.025.
In another aspect the present invention provides a compound of formula I for use as a pharmaceutical, preferably as an antimicrobial, such as an antibiotic, e.g. and an anti-anaerobic.
In a further aspect the present invention provides a compound of formula I for use in the preparation of a medicament for the treatment of microbial diseases, for example of diseases caused by bacteria, e.g. selected from Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Mycoplasms, Chalmydia e.g. and obligatory anaerobes; e.g. including penicillin or multidrug-resistant strains, e.g. of Streprococcus pneumoniae; e.g. including vancomycin-resistant strains, e.g. of Enterococcus faecium; e.g. and including methicillin-resistant strains, e.g. of Staphylococcus aureus. 
In a further aspect the present invention provides a method of treatment of microbial diseases which comprises administering to a subject in need of such treatment an effective amount of a compound of formula I; e.g. in the form of a pharmaceutical composition.
For antimicrobial treatment, the appropriate dosage will, of course, vary depending upon, for example, the active compound of the present invention employed, the host, the mode of administration and the nature and severity of the conditions being treated. However, in general, for satisfactory results in larger mammals, for example humans, an indicated daily dosage is in the range from about 0.5 to 3 g, of an active compound of the present invention conveniently administered, for example, in divided doses up to four times a day. An active compound of the present invention may be administered by any conventional route, for example orally, e.g. in form of tablets or capsules, or parenterally, e.g. in the form of injectable solutions or suspensions, e.g. in analogous manner to Erythromycins, e.g. azithromycin.
The compounds of examples 1, 12, 21, 23, 35 and 52 are preferred compounds of the present invention for use as an antimicrobial agent.
It has, for example been determined that the MIC (xcexcg/ml) of the compounds of examples 1 and 52 (both tested in the form of an hydrochlorid ) against, for example Enterococcus faecalis strain ATCC 29212 is ca. 0.8 to 6.4; whereas, for example ethromycin A, as commeraially available, shows an MIC (xcexc/ml) of ca. 1.6. It is therefore indicated that for the treatment of microbial diseases, bacterial diseases the preferred compounds of the invention may be administered to larger mammals, for example humans, by similar modes of administration at similar dosages than conventionally employed with erythromycins, e.g. erythromycin A or azithromycin.
The active compounds of the present invention may be administered in the form of a pharmaceutically acceptable salt, e.g. an acid addition salt or metal salt; or in free form; optionally in the form of a solvate. The active compounds of the present invention in the form of a salt exhibit the same order of activity as the active compounds of the present invention in free form.
The present invention also provides a pharmaceutical composition comprising a compound of formula I in free form or in the form of a pharmaceutically acceptable salt; e.g. and/or in the form of a solvate; in association with at least one pharmaceutical carrier or diluent.
Such compositions may be manufactured according to a method as conventional. Unit dosage form may contain, for example, about 100 mg to about 1 g.
The active compounds of the present invention are additionally suitable as veterinary agents, e.g. veterinary active compounds, e.g. in the prophylaxis and in the treatment of microbial, e.g. bacterial diseases, in animals, such as fowl, pigs and calves; e.g. and for diluting fluids for artificial insemination and for egg-dipping techniques.
In another aspect the present invention provides a compound of formula I for use as a veterinary agent.
In a further aspect the present invention provides a compound of formula I for the preparation of a veterinary composition which is useful as a veterinary agent.
The present invention further provides a veterinary method for the prophylaxis and in the treatment of microbial, e.g. bacterial diseases which comprises administering to a subject in need of such treatment an effective amount of a compound of formula I, e.g. in the form of a veterinary composition.
For use of the active compounds of the present invention as a veterinary agent, the dosage will of course vary depending upon the size and age of the animal and the effect desired; for example for prophylactic treatment relatively low doses would be administered over a longer time period, e.g. 1 to 3 weeks. Preferred doses in drinking water are from 0.0125 to 0.05 weight by volume, particularly 0.0125 to 0.025; and in foodstuffs from 20 to 400 g/metric ton, preferably 20 to 200 g/metric ton. It is preferred to administer the active compounds of the present invention as a veterinary agent to hens in drinking water, to pigs in foodstuff and to calves orally or parenterally, e.g. in the form of oral or paraenteral preparations.
In the following examples which illustrate the invention references to temperature are in degrees Celsius.
The following abbreviations are used:
The numbering of the mutilin cyclus referred to in the examples is given in the following formula: 